Vertically hanging variety, beneath a white square with the arms, divided white and green. I saw this flag on display (with several others) at a street crossing in Fürstenfeldbruck. Arms from Stadler 1964-1971. (...) Adopted 15.11.1967. Since the county was hardly changed by the 1972 municipal reform, the flag did not change and is still in use. I know that the 'arms-on-white-square' variant is used, but the grant does not say anything about it.

The new arms were granted on November 11, 1976 and are based on some historical facts. The bend is a symbol for the former Cistercian monastery in Fürstenfeld, the arms of the order are black with a chequered bend. The crown symbolises both Duke Lüdwig II of Wittelsbach, who founded the monastery, and
Abbot Pellhammer, who ended the building of the church in 1747. The crown is derived from his personal arms. The bridge is taken from the old arms of the town
of Fürstenfeldbruck (a canting element) [Brücke = bridge].